The present invention relates to an arrangement including circulators for connecting a plurality of microwave transmitters and receivers to a common antenna.
It is well known in the art to connect a plurality of directional radios (transmitters and receivers) to an associated antenna via appropriate antenna combining filters which effect decoupling of the radio devices from one another. The most important components of such antenna combining filters are frequency filters which are tuned to the operating channel of the associated respective instrument or radio devices, and circulators which serve to produce the interconnection of the radio devices (see, for example, U.S. Pat. No. 3,530,471, issued Sept. 22, 1970).
In the conventional system combining filter arrangements (see, for example, German Pat. No. 1,196,254 issued Mar. 10, 1966) the individual transmitters are connected together via a first series connection of circulators and the individual receivers are connected together via a second series connection of circulators. A further circulator, the so-called combining circulator, is provided to connect these two series connections of circulators to a common antenna.